Windows 2003 Pathing for EVA6400

[jeffturl_1]

We have a number of Windows 2003 servers that are presented storage from an EVA6400, the EVA has 4 ports connected, 2 to one fabric and 2 to another fabric. The Windows servers all have dual port HBA's with one port connected to one fabric and the other port to the other fabric.

All Windows Servers are using MPIO fully featured, and the DSM for 6400.

The disks are currently using the default policy of SQST and ALB is set to No.

I notice the active paths reads 4, is this correct? i would have thought it should be 2 with active I/O to the preferred controller and 2 without I/O to the non preferred controller. Or am i missing something here?

Regards
Jeff

[Patrick Terlisten]

Hello Jeff,

four active paths is right. You can do IO over all four paths, but two path are not optimized for IO. This paths are to the non-owning controller of the vdisk what results in a proxy IO. But with MPIO installed the OS should only do IO over the active and optimized paths.

Regards,
Patrick

[jeffturl_1]

Thanks Patrick, i am used to working with vSphere which shows me which paths are to the preferred controller and which are to the non-preferred. Hence why i was confused when the Windows box shows as 4 active paths.

Anyway, in vSphere i use Round Robin pathing policy. Whilst in Windows environment it uses SQST.

I used to use fixed in older versions of ESX so only using one path to the preferred controller. I am not familiar with SQST how does this compare and is it the recommended pathing policy for a Windows 2003 server?

[Uwe Zessin]

You need to turn on ALB. This tells the MPIO to use only optimized paths for I/O.

[jeffturl_1]

Thanks, so i turn ALB on, do i also need to change the pathing policy, is SQST the most appropriate?